Patch "net_sched: remove warning from qdisc_hash_add" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

net_sched: remove warning from qdisc_hash_add

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
net_sched-remove-warning-from-qdisc_hash_add.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Konstantin Khlebnikov <[email protected]>
Date: Tue, 15 Aug 2017 16:39:05 +0300
Subject: net_sched: remove warning from qdisc_hash_add

From: Konstantin Khlebnikov <[email protected]>

[ Upstream commit c90e95147c27b1780e76c6e8fea1b5c78d7d387f ]

It was added in commit e57a784d8cae ("pkt_sched: set root qdisc before change() in attach_default_qdiscs()") to hide duplicates from "tc qdisc show" for incative deivices.

After 59cc1f61f ("net: sched: convert qdisc linked list to hashtable") it triggered when classful qdisc is added to inactive device because default qdiscs are added before switching root qdisc.

Anyway after commit ea3274695353 ("net: sched: avoid duplicates in qdisc dump") duplicates are filtered right in dumper.

---
 net/sched/sch_api.c |    3 ---
 1 file changed, 3 deletions(-)

@@ -275,9 +275,6 @@ static struct Qdisc *qdisc_match_from_ro
 void qdisc_list_add(struct Qdisc *q)
 {
 	if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) {
-		struct Qdisc *root = qdisc_dev(q)->qdisc;
-
-		WARN_ON_ONCE(root == &noop_qdisc);
 		ASSERT_RTNL();
 		list_add_tail_rcu(&q->list, &root->list);
 	}

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/net_sched-remove-warning-from-qdisc_hash_add.patch queue-4.4/net_sched-fix-order-of-queue-length-updates-in-qdisc_replace.patch queue-4.4/net_sched-sfq-update-hierarchical-backlog-when-drop-packet.patch